Abstract: The trace selenium contents in three different brands of milk were determined by wet digestion-atomic fluorescence spectrometry. The results showed that the optimum conditions were HNO3/HClO4 volume ratio of 4：1 at 150 -170 ℃. Selenium concentration curve presented a good linear relationship at the range from 0 to 20 μg/L, R = 0.999 12. The sample recovery was 96.5 %- 104 % and the relative standard deviations were less than 5 %. Therefore, this method is suitable for determination of the selenium in the milk.